1. Field of the Invention
The present invention relates to an exposure apparatus used for transferring a mask pattern onto a photosensitive substrate in a lithography process for making, for example, a semiconductor device, a liquid crystal display device, an image pickup device (CCD or the like), or a thin film magnetic head and, in particular, to an exposure apparatus having a function of controlling its exposure quantity with respect to the photosensitive substrate.
2. Related Background Art
An exposure apparatus is an apparatus for projecting a desired pattern onto an optically sensitive material (photoresist). Such an exposure apparatus is disclosed in U.S. Pat. Nos. 4,908,656 and 5,191,374.